Don't have a lot of time, hopefully I can get more of a write-up later...
Surprised this one hasn't been picked up already (at least I don't think it has - did a quick search and got no results)... In the category of
Western, we select, Fred Zinneman's seminal
High Noon.
One of, if not my fav western ever. Did a lot to establish the revisionist period of the American Wester, playing around with a lot of the traditional elements. One of the most tense climax sequences you'll see in any genre. Just a great, great film that holds up very well over time.